楼上说的对,GRP本身只扩展萨尔茨堡和Basel。但是布鲁塞尔可以买扩展票~“ DB IC Buses to Strasbourg, Prague, Kraków, Antwerp, Brussels, Szczecin, Zagreb and Copenhagen” 就是额外加钱扩展GRP的覆盖范围 详细可以看这份brochure, 链接地址http://www.bahn.de/p_en/view/mdb/bahnintern/international/uebersee/mdb_180025_german_rail_pass_flyer_2015.pdf,希望对你有帮助
德国通票能用于科隆-布鲁塞尔的ICE:
http://www.germanrailpasses.com/passes-prices/pass-extension